1. Field of the Invention
Water spray nozzles have been used in a variety of dust and ignition suppression operations. For instance water spray nozzles have been provided in, on, or adjacent pick boxes for a variety of purposes. In coal mining such purposes are dust suppression; pre-start warning; incendive sparking suppression shrouding, and, on a so-called ventilated rotary cutting head, for air flow inducement to encourage methane dilution and dispersal. In coal transportation, such uses are on belt conveyor spray bars, chutes, and lump breakers.
2. Description of the Prior Art
In mining conditions, whether mining coal, potash or other minerals, or in tunnel driving operations, there is a propensity for nozzle blockage, particularly when a machine is idle for whatever reason. Hence removal, cleaning and refitting is essential if the nozzles are to remain effective, particularly as some machines safety systems monitor water flow and/or pressure and effect machine shut down automatically when monitored parameters signal excessive blockage. Various attempts, successful to greater or lesser extents, have been made to provide "screwless" nozzles, to overcome the known drawbacks of removing and refitting screw-in, screw-out nozzles in mine conditions. Thus, metal pins, wires and staples have been proposed. As a typical coal winning drum would typically carry some 50-70 pick boxes, nozzle removal, cleaning and replacement is a tedious and time consuming operation in the limited confines and lighting of a coal face. There is a demand for an attachment system that is both simple and rapid.